The present invention relates to an occupant position sensing system and more particularly to an occupant system which can identify and track the position of an occupant prior to and during an accident.
Occupant position sensing systems must be able to provide a signal indicative of the position of a main target, such as the torso of an occupant, while ignoring spurious signals that may arise from noise and other objects that might be perceived, by the sensing system, as secondary targets.
An object of the present invention is to design a sensing system and provide a method of operation which is able to track at least a main target, such as a moving occupant, within a vehicle during a crash.
A further object of the present invention is to provide an ultrasonic based sensing system.
Accordingly the invention comprises: An apparatus and method of determining and tracking the position of a main target (an occupant) and secondary targets, comprising the steps of: transmitting a signal T.sub.1, of determinable period toward the location of the occupant, generating and storing a first index of data indicative of the time any received signal exceeds a determinable threshold; separating the data within the first index into definable data groups indicative of individual received signals representing potential targets; determining, in relation to each transmitted signal T.sub.1, a common group time of receipt T.sub.c for each data group; correlating the group time of receipt to the position of the main target and secondary targets occupant.
Many other objects and purposes of the invention will be clear from the following detailed description of the drawings.